Full-motion video generation systems decode and display full-motion video. In the computer context, full-motion video is the rendering of clips of television programming or film on a computer screen for the user. (This document will use the term ‘full-motion video’ when referring to such television or film clips to distinguish such full-motion video from the reading of normal desktop graphics for generation of a video signal for display on a video display monitor.) Full-motion video is generally represented in digital form as computer files containing encoded video or an encoded digital video stream received from an external source. To display such full-motion video, the computer system must decode the full-motion video and then merge the full-motion video with video data in the computer system's main frame buffer. Thus, the generation of full-motion video is a memory size and memory bandwidth-intensive task. However, the display of full-motion video is a standard feature that is now expected in all modern computer systems.
In a full personal computer system, there is ample central processing unit (CPU) processing power, memory, and memory bandwidth in order to perform all of the needed functions for rendering a complex composite video display signal. For example, the CPU may decode full-motion video stream, the CPU may render a desktop display screen in a frame buffer, and a video display adapter may then read the decoded full-motion video, combine the decoded full-motion video with the desktop display screen, and render a composite video display signal.
However, in small computer systems, where the computing resources are much more limited, the task of generating a video display can be much more difficult. For example, mobile telephones, handheld computer systems, netbooks, and terminal systems will have much less CPU, memory, and video display adapter resources than a typical personal computer system. Thus, in a small computer the task of rendering a composite video display can be very difficult. It would therefore be desirable to develop methods of improving the display systems for small computer systems.